Une table MySQL 4.0 peut-elle avoir à la fois des colonnes d'horodatage créées et mises à jour ?

Having a Created and Last Updated Timestamp in MySQL 4.0

Question:

Can a table in MySQL 4.0 have both a Created and a LastUpdated timestamp column? Or must the LastUpdated field be manually set during each transaction?

Answer:

In MySQL versions 4.0-5.6.4, only one TIMESTAMP column per table could be automatically updated to the current date and time, either as a default value or as an auto-update value. This meant that you could not have both a Created and a LastUpdated timestamp column with these automatic updates.

However, with the release of MySQL 5.6.5, this restriction was lifted. Any TIMESTAMP column can now have any combination of DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses.

Therefore, in MySQL versions 5.6.5 and later, it is possible to have both a Created and a LastUpdated timestamp column with the following schema:

CREATE TABLE `db1`.`sms_queue` (
  ...
  `Created` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `LastUpdated` TIMESTAMP NOT NULL ON UPDATE CURRENT_TIMESTAMP,
  ...
);

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